East Antarctica. Home to most of the world’s remaining land ice. Scientists previously thought that this last bastion of somewhat stable ice in the world would only slowly succumb to the slings and arrows of human-caused climate change. That its ice giants would still sleep for some time — giving the world more time to stave off or avoid worsening rates of sea level rise. Unfortunately, new evidence reveals that this is not the case. That the best time to act on sea level rise was 20+ years ago, and that the second best time to act, in cutting fossil fuel based CO2 emissions, is now.

(The Totten Glacier itself contains enough ice to raise seas by 11-13 feet, which is comparable to all of West Antarctica. Its glacial catchment, however, is larger. Image source: Australian Antarctic Division.)

The primary cause of Totten’s melt acceleration is wind-diven warm ocean currents starting to encroach upon the glacier. These warm currents dive deep and then upwell near the glacier faces and along their weak underbellies. What the new research shows is that CO2-based warming from fossil fuel emissions is increasing the heat content of the waters even as it drives the strengthening of winds that bring these waters into more frequent direct contact with glaciers like Totten.

“Upwelling is driven not purely by the broad-scale magnitude of wind, but by the gradient in wind—how strong the wind is at one latitude versus how strong it is at a different latitude. And CO2 in the atmosphere is modeled to increase the wind gradient around Antarctica, and then therefore increase upwelling around Antarctica.”

Glaciers are very difficult to move when sitting still. But once they get moving, it’s very difficult to stop what amounts to a moving mountain of ice. Forces now encroaching upon Antarctica are now conspiring to trigger the seaward movement of various gigantic glaciers. Once that happens, a certain amount of sea level rise gets locked in. This new research indicates that Greenland and West Antarctica aren’t the only systems that are capable of seeing glaciers released in this fashion. With the new research from Totten, East Antarctica is starting to come into play as well. And that means that multi-meter sea level rise this Century is not out of the question.

29 Comments

wili

Thanks for posting on this. Not only will this affect sea levels around the world, there are clear connections between the poles. If nothing else, increased sea levels will push more warm Pacific Ocean waters through the Bering Strait into the Arctic Basin. Much discussion on this now going on over at asif: https://forum.arctic-sea-ice.net/index.php/topic,12.msg133510.html#msg133510

coloradobob

Significantly more ice in Greenland’s glaciers may be exposed to warming ocean waters than previously thought, new research suggests. Indeed, more than half the ice sheet may be subject to the melting influence of the sea.
These are the latest conclusions of a detailed mapping project exploring the topography of the seafloor and bedrock around and beneath Greenland’s glaciers.

coloradobob

NASA Map Shows Greenland’s Glaciers Melting Faster, Number is Four Times More Than Estimated

A new map released by NASA has shown that Greenland’s glaciers are melting at an alarming pace. The number of melting glaciers is four times more than what was estimated in the past. The map represents the coastal sea floor and the surface under the sheets of ice.
The map was released ahead of COP 23 summit whose agenda is the implementation of the Paris Agreement. Paris Agreement entails combating global warming and reducing the environmental temperature by 2 per cent.

coloradobob

Left: Greenland topography color-coded from 4,900 feet (1,500 meters) below sea level (dark blue) to 4,900 feet above sea level (brown). Right: regions below sea level connected to the ocean, either shallower than 600 feet (200 meters, light pink); between 600 and 1,000 feet (300 meters, dark pink); or continuously deeper than 1,000 feet below sea level (dark red).
Courtesy: University of California
The map was created by scientists at the University of California, NASA and 30 other institutions, reported Geospatial.com. The website said that the it was the most accurate high-resolution map of Greenland’s coastal seafloor and bedrock.

Erik Frederiksen

The NASA glaciologist Eric Rignot said recently that Marine Ice Sheet instability is happening on Greenland as well as West Antarctica, and that Greenland has about 3m worth of ice grounded below sea level.

Raul M

Yes and a thermal electric jacket could help me to understand why it’s still ok for it to be so freaking hot. The idea of the thermal electric cooler is a nice one and a jacket to accept the cool is nice. Course a little dolly to carry the batteries and solar panel, if needed, is nice too.

Erik Frederiksen

All it took was a temperature rise of 1 degree C to destroy the floating ice shelf which constrained the flow of the Jakobshavn Isbræ Glacier which drains part of the Greenland Ice Sheet by calving ice bergs into the ocean.

Globally ice shelves constrain about 25m of sea level rise equivalent of ice grounded below sea level where warming oceans can access it and it can make icebergs.

It’s minus 50 C on parts of Antarctica, warm it up to minus 45 C and who cares? But it’s at the melting point at the coast.

The glaciologist Richard Alley said that a 1 degree C rise in temperature is a big insult to an ice shelf almost anywhere on the planet.

When the Larsen B ice shelf on the Antarctic Peninsula broke up in 2003 the glaciers behind sped up 6-8 fold and are still flowing at that accelerated rate today because the cork was removed. Luckily there’s comparatively little ice there.

If we sped up all on Antarctica’s glaciers by a factor of 6.5 sea level rise would be 4m per century, the same which occurred 14,600 years ago for 4 centuries during Meltwater Pulse 1A.

Jim

Thanks for this Erik. What’s your take on Greenland’s late season melt events which seem well outside of the 3 sigma probability envelope? (I’m guessing about the 3 sigma since nsidc uses interdecile and interquartile measurements.)

We’re warming at a considerably faster rate than at the end of the last ice age. At some point, we hit those melt thresholds. Meltwater pulses during the temperature rise following the last glacial period indicate that the range of concern is 1.5 to 2.5 C warming. We are swiftly approaching that threshold.

Ice shelves generate back-pressure — preventing the ice behind it from moving. They are like corks in full bottles tilted sideways. Remove them and the ice gushes forward. Warming at the margins and in the ocean facilitates this movement. Melt itself amplifies the upwelling currents through the fresh water wedge effect. And, apparently, now we know that rising temperatures due to increased CO2 also help to enhance the wind patterns that drive warm water currents toward the ice. A good number of feedbacks appear to be visible in this process.

Generally, if you look at the paleoclimate record, SLR rates tend to come in pulses. So periods of slower SLR can be rapidly followed by periods of far more rapid SLR as these various glacial systems speed up in concert.

Surface ponding, rainfall over ice, and warm winds over ice have an added effect that is not as well understood by the science at this time. Would be concerned about ice dams and very large melt lakes at a certain point. However, the primary present forcing of concern is occurring at the margins and in the ocean adjacent to and beneath the sea fronting glaciers.

Flinders Island going for green with renewable energy hub, farewells dirty diesel
Following the lead of King Island which is 100%
Mr Massie said, based on the King Island results, Flinders Island’s power supply would become significantly more reliable.
“On King Island they had eight to 10 blackouts a year traditionally, and with the new system in place that has been one black out in two years,” he said.
“We expect that to be the case with Flinders as well.”

Major incentive for these islands to transition to renewables. On the present course, with regards to price alone, the rest of the world will be in a similar position rather soon barring extraordinarily bad energy and climate policy.

“Up until this year, in 118 years of weather records, Dallas had never hit 90 degrees during November. It just did so three times in the past four days.

The heat that scorched Dallas is part of record-setting heat wave that has consumed most of the Lonestar State to start November. In Austin, Houston and San Antonio as well, temperatures soared some 10 to 20 degrees above normal, levels more typical of September.”

Thanks for this, Greg. The thing that gets me about this one is that it almost seemed like the weather didn’t even try for these records. It was a blip in the usual pattern that produced this heat. Not some massive strange weather system. Looks like these temps will happen with some regularity now at this time of year. And I wouldn’t be surprised if a weird weather system like some massive blocking high blows these numbers out of the water within the next decade.

A new NASA study adds evidence that a geothermal heat source called a mantle plume lies deep below Antarctica’s Marie Byrd Land, explaining some of the melting that creates lakes and rivers under the ice sheet. Although the heat source isn’t a new or increasing threat to the West Antarctic ice sheet, it may help explain why the ice sheet collapsed rapidly in an earlier era of rapid climate change, and why it is so unstable today.